The widespread use of poured concrete in buildings has many benefits over buildings made from other materials, such as wood. These benefits include a reduction in fire risk, an increased speed and ease of production and low noise transmission between floors. A variety of devices have been developed to assist in the attachment of fittings and equipment, particularly electrical and plumbing fittings, to such buildings. Although it is relatively easy to drill holes and to insert anchors in concrete, it is time consuming relative to simply driving a nail or a staple in wood.
This problem has led to the development and marketing of products to the construction industry known as RAM SET (Trademark) guns, power hammers or HILTI (Trademark) guns. The concept common to all these devices is the use of an explosive or propellant charge which is detonated inside a hand-held gun, the propellant charge being used to propel a metal object such as a threaded bolt into a hard surface such as a concrete wall. These guns are extensively used in the construction of concrete buildings such that plumbing pipes and electrical cables may be hung on fastening devices fixed in concrete. The propellants can also be used in cattle stun guns and starter pistols.
Manufacturers currently manufacture the cartridges or containers for the explosive charges by deep-drawing brass into a shape resembling a small caliber bullet except that there is no slug at the top of the bullet. At least one manufacturer inserts the cartridges into a plastic strip so that the gun can be used in a semi-automatic fashion rather than a single shot mode. Typically, these devices include drive engaging means, such as notches, formed on the strip so that the strip can be advanced by the gun and properly aligned with the firing hammer or detonating pin in the gun to subsequently explode the respective charge.
One problem with the prior art apparatus is its relatively high expense. Typically and as described, the magazine component is a two component system comprising a plastic carrier having a series of holes and non-ferrous brass cartridges that fit the holes. Brass is expensive and the necessary deep-drawing and annealing of brass to form the required shape for the cartridge is also unduly complex.
Caseless charges have been designed to avoid the expense of deep drawing non-ferrous metals. Disadvantages have been experienced with such caseless charges, however, because of ignition difficulties. One such difficulty is that ignition of adjacent propellant charges has occurred due to a lack of a combustion sealing mechanism between the cartridges. This is, of course, dangerous and unsafe. A caseless charge magazine which reduces or eliminates this danger is disclosed in U.S. Pat. No. 4,406,079 which describes a strip of caseless charges wherein the propellant charge is displaced into the gun for ignition. The system, however, is incompatable with the more widely used types of guns and it is an inconvenient requirement to position each propellant in its own chamber prior to ignition. A further problem with such caseless charges has been that methods to initiate detonation generally utilise initiation techniques which are not as reliable as rim fire techniques. Rim fire techniques are preferable since they are in far wider use.
In the aforementioned U.S. application Ser. No. 138,431, there was disclosed apparatus used to reduce the costs associated with brass cartridges and to allow the manufacture of the magazine to proceed more efficiently. To that end, a cartridge member made from a plastic material and having a cylindrical-like cavity therein to hold the propellant was disclosed. The cartridge member had an integrally formed annular skirt and a circular opening around the periphery of the annular skirt, the opening being adapted to receive and hold a percussion cap closure which was easier to manufacture and utilised less material than many cartridges of the prior art. One of the percussion cap closures, however, continued to be made from brass. In addition, a plastic closure member was also disclosed rather than a closure member made from brass.
While these apparatuses reduced the need for a non-ferrous material and allowed easier manufacture of cartridges, there was still the need for metal to allow detonation of the primer. The requirement for metal makes the manufacturing process unnecessarily expensive and complex.
The following references disclose subject matter which is pertinent to the technology set forth in the present specification.
U.S. Pat. No. 2,918,868, Ringdal, issued Dec. 29, 1959 discloses an invention relating to a cartridge comprising a base having a tubular extension and a case which consists of relatively elastic flexible synthetic resin material, such as polyethylene or polyvinylchloride. The attachment of the case and cartridge base to each other is secured by means of a bead on the one member in engagement with a corresponding groove in the other member.
U.S. Pat. No. 3,318,245, Ferri et al., issued May 9, 1967 discloses strip ammunition for toy guns wherein a plurality of discrete explosive charqes are contained in container means. Stalk means interconnects each container means. Stop means are formed on the stalk means for engagement by an advancing means of a toy gun. In this way the strip can be advanced by the space between each container means each time the gun is fired.
U.S. Pat. No. 4,294,173, Ferri, issued Oct. 13, 1981, discloses ammunition for a toy-weapon comprising an injection molded support having seats for explosive charges. The charges are sealed within the seats by a separate cover for each seat. The covers are injection moulded simultaneously into the seats of the support.
U.S. Pat. No. 3,349,710, Sposimo, issued Oct. 31, 1967 discloses a strip carrier for explosive socket caps for toy guns. The explosive is encased in wells which are capped by a series of caps strung together in series.
U.S. Pat. No. 3,583,087, Huebner, issued June, 1971 discloses a certain design of magazine.
U.S. Pat. No. 3,611,870, Udert, issued October, 1971, discloses a cartridge magazine construction in which the cartridge is placed in a narrow band having a plurality of tubular projections formed therein. Each projection holds a single cartridge.
Gawlick et al. have been active in this area. U.S. Pat. No. 3,625,153, issued December, 1971, discloses a plurality of plastic propellant cases formed in series on a base.
U.S. Pat. No. 4,036,103, Gawlick et al., issued July 19, 1977, disclose a magazine apparatus for accommodating propellant charges including a flat coilable metal strip having a plurality of holes extending transversely therethrough for accommodating the insertion of cartridges. Cartridge holding collars are formed at each of the holes by bulging or plastically deforming the strip in the region of these holes so as to form a clamping seal spaced from the plane of the strip for clampingly engaging cartridges held at the strip. Various preferred embodiments include various cross-sectional configurations of the holding collars. The method of making the magazine apparatus includes forming the collars by a multiple-step bulging process wherein the last bulging step is formed by the cartridges as they are inserted into position on the strip.
U.S. Pat. No. 4,098,169, Gawlick et al., issued July 4, 1978, discloses an ammunition belt apparatus for accommodating propellant cartridges includinq a flexible, coilable belt strip, a plurality of holes extending transversely through the strip and spaced from one another in the longitudinal direction of the strip. Clamping means are associated with each of the holes for clamping a cartridge to the strip with portions of the cartridge extending through one of the holes. Parts of the clamping means are formed separately from the strip and the cartridge. In preferred embodiments, the clamping means includes a tubular casing formed separately from the strip for each of the holes. The tubular casing press-fittinqly engages a respective cartridge for holding the cartridge in position on the strip with the casing. A cartridge rim clamps the strip therebetween.
U.S. Pat. No. 4,056,063, Walser et al., issued Nov. 1, 1977, discloses a magazine for use in an explosive powder driven bolt setting gun. A cartridge holding space for a caseless charge is formed by the combination of a cartridge recess in a band-shaped magazine body and a torus-shaped body superimposed on the magazine body to form an extension of the recess. Various configurations of the cartridge holding space and the exterior of the torus-shaped body can be used. A variety of openings can be provided through the cartridge holding space to prevent destruction of the magazine parts when the caseless charge is ignited.
U.S. Pat. No. 4,406,079, Buechel, issued Sept. 27, 1983, discloses a magazine for caseless propellant charges, such as those used in a fastening element setting device. The magazine consists of an elongated strip-like member. Cut-outs are provided in the strip-like member and a caseless charge holder is secured in each cut-out by webs. A caseless charge and the holder are displaced out of a cut-out when a sufficient force is directed against the holder to separate the webs from the strip-like member.
U.S. Pat. No. 4,565,114, Burdick et al., issued Jan. 21, 1986, discloses a cartridge magazine for holding cartridges for feeding to the barrel of an explosion driven fastener setting tool. The magazine comprises an elongated flat flexible strip or band preferably made of an inexpensive material such as plastic. The strip includes a plurality of stepped projections defining cartridge holding recesses arranged at equally spaced locations along the strip and lateral recesses for advancement. Each cartridge holding recess is defined by a stepped projection extending upwardly from the strip which on its exterior is stepped inwardly in a direction toward the tip of the cartridge. The angular taper of each of the outside walls of this portion on the cartridge magazine is slightly less than one cone angle of the cartridge chamber of a gun barrel with which it is to be employed. In this way there is more than one sealinq point between the projections and the inner wall of the cartridge chamber.